A small print shop for PNG files

What it does

• The PNG compressor reduces images to a palette of up to 256 colours with transparency kept, then optimises them losslessly with oxipng.
• The chunk inspector shows every chunk, offset and checksum in a file, decoded.
• The metadata remover strips text, timestamps and EXIF without touching the pixels.
• Repair PNG fixes damaged files and salvages what survives of cut-off ones.
• Make PNG transparent removes a background colour; the trimmer crops empty borders.
• The APNG maker builds animated PNGs and takes them apart.

How it works

The pages are static files. When you open an image, it is read by JavaScript in your browser and processed in background workers on your own device. The PNG decoder, encoder, palette quantizer, chunk parser and APNG code are written for this site; compression uses the fflate library and the optional lossless pass uses oxipng compiled to WebAssembly. Nothing you open is sent to a server, so the tools keep working offline once a page has loaded.

Honest limits

Palette compression is lossy by design, and the comparison view is there so you can judge it. The repair tool reports what it could not recover rather than guessing, and the background remover works on plain backgrounds, not on photographs of busy scenes.

Who runs it

PNGMender is one of a family of small single-purpose tool sites; some of its sister sites are linked at the bottom of every page. There are no accounts, no ads and no cookies. Page views are counted with Cloudflare Web Analytics, as explained on the privacy page.